Help to all cat lovers! What can I do?

I have a stray cat that has come to our house and we now have had her for almost a year because she has gotten pregnant twice and we can't afford to spay her! We have 4 cats of our own and she has been sneaking into our house someway, we're not sure how, and fighting with them. My husband dumped her a week ago and said he took her out so far she would never come back. I was furious with him! She found her way home last night and I am afraid he will kill her if he sees her here. I have tried to get shelters here in Oklahoma to take her but they say they are full and no person wants a one eyed cat! She is sweet and gets around great though. We call her "Winky". What can I do? Any advice?